Commonly owned U.S. Ser. No. 09/303,550 entitled xe2x80x9cVACUUM IG PILLAR WITH DLC COATINGxe2x80x9d filed May 3, 1999 now U.S. Pat. No. 6,326,067; Ser. No. 09/404,659 filed Sep. 24, 1999 entitled xe2x80x9cVACUUM IG WINDOW UNIT WITH PERIPHERAL SEAL AT LEAST PARTIALLY DIFFUSED AT TEMPERxe2x80x9d now U.S. Pat. No. 6,336,984; and Ser. No. 09/416,886 entitled xe2x80x9cVACUUM IG WINDOW UNIT WITH DUAL PERIPHERAL SEALxe2x80x9d filed Oct. 13, 1999 pending, are all hereby incorporated herein by reference.
Vacuum IG units are known in the art. For example, see U.S. Pat. Nos. 5,664,395, 5,657,607, 5,891,536 and 5,902,652, the disclosures of which are all hereby incorporated herein by reference.
Prior art FIGS. 1-2 illustrate a conventional vacuum IG unit 1 wherein the pump-out tube is provided in an aperture of hole formed in a major surface or face of one of the glass substrates. IG unit 1 includes two spaced apart sheets of glass 2 and 3 which enclose an evacuated or low pressure space 10 therebetween. Glass sheets 2 and 3 are interconnected by peripheral or edge seal of fused solder glass 4 and an array of support pillars 5. Pillars 5 space the glass sheets 2 and 3 from one another thereby allowing low pressure space 10 to be defined therebetween.
During a known vacuum IG manufacturing process, solder glass is initially deposited around the periphery of the IG unit in an L-shaped step that is formed by virtue of the upper sheet being slightly smaller in dimension than the lower sheet as shown in FIGS. 1-2. The entire assembly including sheets 2, 3 and solder glass seal edge material is then heated to a temperature of approximately 500xc2x0 C. at which the solder glass melts, wets the surfaces of the glass sheets, and flows into the space between the sheets forming hermetic peripheral edge seal 4.
Pump out tube 8 passes through a hole in glass sheet 3 and is sealed by solder glass 9 to an inner major surface of sheet 3. Cavity 11 is machined into glass sheet 2 in order to accommodate the interior end of the pump out tube. A vacuum is attached to tube 8 so that the interior cavity 10 between sheets 2 and 3 can be evacuated to create a low pressure area. After evacuation, the outermost end of tube 8 is melted to seal in the vacuum.
Unfortunately, the presence of pump-out tube 8 and its corresponding sealing material 9 in a viewing area of the window unit as shown in FIGS. 1-2 may be aesthetically displeasing to some users. Furthermore, the drilling of the hole in the face of substrate 3 as shown in FIG. 2 may cause yield loss due to glass breakage or cracking. Thus, it would be desirable to provide the pump-out tube in a location where it would not be easily seen by viewers looking through the window unit, and/or at a location where yield loss could be reduced.
FIGS. 3-4 illustrate another conventional vacuum IG unit, wherein the pump-out tube is provided at an edge or side of the unit. See also U.S. Pat. No. 5,657,607, incorporated herein by reference. Again, the vacuum IG unit includes peripheral or edge seal 4, pillars/spacers 5, glass substrates/sheets 2 and 3, low pressure space 10, and pump out tube 8. Sheet 2 includes recess 13 defined therein for getter 14. Unlike the vacuum IG unit of FIGS. 1-2, the pump out assembly 15 of FIGS. 3-4 is on the side or edge of the unit. Channel 16 is machined into respective mating surfaces of the two sheets, and pump-out tube 8 extends from the side between the two sheets.
Unfortunately, the pump-out assembly of FIGS. 3-4 is burdensome and difficult and/or costly to manufacture.
It is apparent from the above that there exists a need(s) in the art for a vacuum IG unit, and corresponding method of making the same, including a pump-out structure positioned in a manner so the :window unit is aesthetically pleasing. There also exists a need in the art for a vacuum IG unit including an edge or side mounted pump-out structure that is easy and/or simple to-manufacture.
This invention will now be described with respect to certain embodiments thereof, accompanied by certain illustrations.
An object of this invention is to provide a vacuum insulating glass (IG) unit including a side or edge mounted pump-out structure.
Another object of this invention is to provide a vacuum IG unit including a side or edge mounted pump-out tube, which is cost efficient to manufacture and/or improves yields relative to certain prior art.
Another object of this invention is to provide a vacuum IG unit including a pump-out insert structure that may be positioned proximate to an edge of a glass sheet prior to formation of the hermetic or other edge seal.
Another object of this invention is to fulfill any or all of the above-listed objects and/or needs.
Generally speaking, this invention fulfills any or all of the above described needs or objects by providing a thermally insulating glass panel comprising:
first and second spaced apart glass substrates defining a low pressure space therebetween having a pressure less than atmospheric pressure;
a plurality of spacers disposed between said first and second glass substrates for spacing said substrates from one another in order to maintain said low pressure space therebetween;
a pump-out insert including an elongated aperture defined therein, said pump-out insert at least partially located on an approximately L-shaped step or ledge defined by the first and second glass substrates;
a pump-out tube disposed at least partially within said elongated aperture of said insert; and
an edge seal at least partially provided in said approximately L-shaped step or ledge for hermetically sealing said low pressure space, and wherein at least a portion of said edge seal is provided over at least a portion of said pump-out insert.
This invention further fulfills any or all of the above described needs or objects by providing a thermally insulating glass panel comprising:
first and second spaced apart glass substrates defining a low pressure space therebetween having a pressure less than atmospheric pressure;
a plurality of spacers disposed between said first and second glass substrates for spacing said substrates from one another;
a pump-out insert including an aperture defined therein, said pump-out insert at least partially located proximate an edge of one of said first and second substrates;
a pump-out tube disposed at least partially within said aperture of said insert; and
an edge seal for sealing said low pressure space, and wherein at least a portion of said edge seal forms a sealing interface with said pump-out insert.
This invention further fulfills any or all of the above described needs or objects by providing a method of making a vacuum insulating glass (IG) window unit comprising:
providing first and second glass substrates;
providing an array of spacers disposed between the first and second substrates for spacing the substrates from one another so as to define a space therebetween having a pressure less than atmospheric pressure;
providing a pump-out insert structure including a body with a pump-out tube passing at least partially therethrough;
positioning the pump-out insert structure proximate an edge of at least one of the first and second glass substrates; and
after said positioning step, depositing an edge seal material so as to at least partially contact the insert structure, and forming an edge seal for hermetically sealing the space between the substrates.